Latching means for die set retainers



Dee. 18, 1956 w. J; BLAZEK LATCHING MEANS FOR DIE SET RETAINERS FiledNOV. 8, 1955' /0 INVENTOR W'JfilaZek United States Patent '0 LATCHINGMEANS FOR DIE SET RETAINERS William J. Blazek, New Lexington, Ohio,assignor to Lempco Products, Inc., Bedford, 01110, a corporation of Ohio7 Application November 8, 1955, Serial No. 545,694 8 Ciaims. (Cl. 164--118) This invention relates to guide appliances for the die sets ofpunch presses and other reciprocatory machine tools.

A punch and die set is an assembly consisting of an upper member calledthe punch holder or plate and a lower member called the die holder orplate. The lower or under surface of the punch holder and-the upper ortop surface of the die holder are those on which the punch and diesections of a finished punch press tool are mounted, although thesepositions are sometimes reversed. In use, the die holder is clamped tothe bed or bolster plate of the punch press, while the upwardlyextending punch holder shank is fastened in the clamping hole providedtherefor in the sliding punch press ram. The tool is actuated by thereciprocating motion of the ram. Mating guide posts and bushings of anassembled die set assist in maintaining tool alignment during diesetting and the operation of the tool in the punch press.

These guide posts and bushings are employed in maintaining the punch anddie details in true alignment or registry during ram-producedreciprocatory movement of at least certain of the ball bearings thereinare disposed under compressive loading forces.

Accordingly, it is an object of the invention to provide an antifrictionguide assembly for die sets wherein improved means are provided forefiecting proper position- 7 ing of the bearing-carrying retainers ofsuch guide assemthe punch and punch holder relative to the die and dieholder. In conventional constructions, the posts are of plaincylindrical formation and are carried by and depend rigidly inrelatively spaced order from associated punch holders. These dependingpostsare received and have a close working fit in longitudinal holes orbores formed in cooperative die holder mounted stationary bushings. Theoperation, longevity and accuracy of such plain guide posts and bushingshave been improved by interposing pressure-loaded antifriction bearingsbetween annularly spaced surfaces of the posts and bushings, asdisclosed in the prior patent to Connor, No. 2,422,774, granted June 24,1947.

In such antifriction guide devices, die alignment is obtained byproviding one of the holders, usually the punch holder, of a die setwith a bushing having a cylindrical bore formed therein for receiving acylindrical coaxial post provided on the other holder when relativemovement of the holders during Working strokes of the press takes place.Undesired lateral motion in such guide devices is precluded by providingeach device with a tubular retainer or' sleeve carrying a plurality ofspaced ball elements of uniform diameter, each of the elements having adiameter slightly greater than the width of the annular space formedbetween the post of the appliance and adjacent inner cylindrical surfaceof the bushing bore repress, and at the same time to maintain theretainers U throughout such stroke movements in positions in whichblies, whereby to cause the retainers to be maintained inalignment-producing and antifriction engagement with associatedstationary and movable guide members.

Another object of the invention is to provide an improved guiding andalignment-maintaining assembly for machine press die sets having movablebearing-carrying retainers disposed in coaxial relation withinterfitting stationary and movable guide members, and wherein positiveand simplified means are provided for maintaining such retainers, at allstages of relative movement of said members, in predetermined operativeorder with respect to said members, whereby to maintain at least certainof the bearings of said retainers under confined conditions ofcompressive loading and yet to permit the same to move longitudinally ofthe guide assemblies concomitantly with the movable members thereof butat a different rate of linear speed.

A further object is to provide the ball-bearing-carrying retainers ofsuch guide assemblies with yieldable stop means adapted for engagementwith associated stationary members of the assemblies, whereby todetermine proper initial operating positions of the retainers inadmitting of antifriction retention thereof in association with theinterfitting stationary and movable members of the assemblies throughouttheir operating strokes, said stop means being automatically retractableto assume inactive positions when engaged by said members. duringperiods-of relative longitudinal movement therebetween,

For a further understanding of the invention, including additionalobjects, constructional andoperational features and advantages thereof,reference should now be had to the following description andaccompanying drawing,

wherein: Y

Fig. 1 is a view partly in side elevation and vertical section of anantifriction guide assembly for machine press die sets, and illustratingthe bearing retainer stop and locating means of the present inventionincorporated therein;

Fig. 2 is a fragmentary detail vertical sectional View disclosing on agreater scale one of the enlarged ballbearing-receiving seats of anantifriction guide assembly retainer formed in accordance with thepresent invention, and showing the ball-bearing occupying an enlargedseat resiliently displaced in-an outward direction for retainer- Fig. 4is a view similar to Fig. 1 and illustrating another modified form ofthe present invention, wherein the stop means for indexing the operativepositions of the bearing retaining members comprise spring-pressed postshoulderengaging catch devices separate from the bearings of the sleevemembers;

.Fig. 5 is a fragmentary detail vertical sectional view on an enlargedscale of one of the catch devices of Fig. 4 and associated parts; a

Fig. 6 is a detail plan view' of a resilient split ring or band adaptedfor use in connection with the foregoing stop and positioningdetermining devices. Referring to the drawings by numerals, and moreparticularly to the. disclosure contained in Figs. 1 and 2, the

movable punch and stationary die holders 10 and 11,

1 respectively, of a die set, are provided with one or more antifrictionguide assemblies 12. The latter are employed for maintaining the holders1!) and 11', and parts carried thereby, in proper alignment or positionsof :r'elative registryduring working movements of a p'un'lchfpress, orother machine-tool on which such a die set is mounted.

In this instance, each assembly is shown as comprising acylindrical'bushing 13 rigidly; carried by and arising" from an openingformed in the die holder 11 of the die set The bushing provides aninternal cylindrical bore and the groove 21, the ring or band 22 .is ina somewhat circumferentially contracted state. so that its expansiveenergy is directed outwardly on the ball elements 18a, causing thelatter to be seated in the relatively restricted outer portions of theseats or openings 17d. This 'is done r so that the elements 18a will bemaintained in'contact with the shouldered edge 20 withsuflicientrfirmness'to' V sustain the weight of the retainer and topreventjits drop- 7 7 ping intotheilower part 'of'the bushing bore'14;

14 of uniform diameter throughout its length, the bore having machined:ground, hardened and/ or polished Wall surfaces held to closedimensional tolerances. Thernovable plate 15 of each assembly carries tafixed,rigid, depending pin or 'post; 15 having cylindrical outerwall surfaces-of uniform diam'eter substantially throughout the As: the post '15descends: firom its elevated position at the start of'itsworking stroke,the. same moves into pres v jsure-loadingcontact withf'the ball elements18 disposed immediately below the elements 1811. -Since the elements 18cannot move radially outwardly of the retainer after length thereof,these surfaces being heldwithi'n closefdi-j,

n ensional' limits byfmachining and otherwise finishing, and hardeni'ngthe same to a true cylindrical contour.

Mounted for linear movement 'in each guide assembly the manner oftheselernents.ltimibutfare cornined positively in their seatsagainstYsuch radial movement,and are, also, additionally' heldbyfpressing against the wall surface of the bore 14, it will betevidentthat the ball ele- 21 3 ,a tubular, sleeve-like, bearing retainer 16',the' latter f V having'accurately finished inner and outer cylindrical 7surfaces of uniform diameterhardened, polished or otherwise treatedafter the manner of forming the complemental surfaces of the post andbearing members. Each i retainer is formed with a plurality oftransverse relatively spaced openings (17 constituting seats for therotatable retention of a plurality of ball-bearing elements'IS. The I: a

wall thickness of each retainer is less than the radial width of anannular space 19 formed between each interfitting pair of guide bushingsand posts when the latter are disposed in relatively telescoped orderEach bear i V 7 ing element, however, possesses a diameter slightlygreater 7 than the radiaI width of the space'19 rec'eiving the same;

This enlarged diameter is important in the operationnof guide appliancesof this character, in'that when a'post 15 descends so that" its lowerend is' positioned jn'the upper part of the innep bore 20 of canassociated retainer', 1 andzat theisame timeinthe-uppfer'part ofthe'bore 14 of 'Janfassociated guide bushing 13, certain oi the ballbear; f

i pthpost has reached itsffull upwardipositionof travel,- i 5 atwhich'time' the above-definedcycle may be repeated. Q 3

' ingielements'will be engaged by the'post and crowded therebyintoengagemjent with the inner bushing wall to 7 place the post-engagedball elements of the sleeve under :compressive forces. The ball elementsso engaged' are rotatei'with the result that the-retainer 'moves downwardly conconiit'antly with the descending post, buttat a lower rate oflinear travel. juclrmotion is continued as v the ball elementsareprogressivelyjengaged by the descending post, producing a positiveguiding action where- V in lateralrnotionis eliminated andaccuracythereby obe tained inpunch'and die'registry."

' and stationary members of the die setiwhic'h' members have been hereshown as comprising the movablefpostflfi' and the stationary bushing 13;although this order might be reversed if desired: T

WhenIthe post '15- is elevatedto assume a startingposi tion, the loweriend 'thereof is"prferably positioned so g V ,mediately'- belowthe'eleme'nt's Q1819, thereby: placing: the

that it does, not confine one or-m'ore'bearings 18 by apply-1 i 1 i i aing compressive forces' thereto. Undentheseiconditions I of relativerelease'and to prevent theretainer fromdrop; ping 'gravitationallyintothe bushing bore 14,, certain of V the bearings,18, those here shown at18a, a-re disposed] in horizontaltorder forcontactwithftlieiiuppcnfshoulder storming edge 26: of the bushing. The bearingsISa are I pressedoiltwardlyandradially ofethe retaineribody by; e

i lateral r novement in the'enlarged openings'tconstituting V the seats17a. The relatively enlargedjinneiiendsw "of the' openings'17a-communicatewith'an ann'ulargroove" 21in which-'isjpositioned a splitresilient' or, band" I L Another variation ,of thisiconstructionisfdisclosedj 5 V H Figs. ands5 vjwherein, the: annular groove 24,formedqf 1 in, the bottom portion "of the ,post:15:,' is provided withfaV shoulder 25 for engagenien'tj with the inner beveledtends' 'of aplurality: 'of radially positioned latchjmembers26.

'ments18 so engaged are positivel'y'rotated1and placed 20 under loadingcompression by the descending post. The positiverotation thus impartedto the compressively loadf' ed ball elements causes the retainer todescend and move simultaneously with the post'bnt'at a lower" rate oftravel, thus overcoming the actionof the spring 22 in cau sing the ballelements 18a to move radially inwardly to clear 'the shoulder 20. 7

Under these conditions, the support of thefloating retainer no'longerdepends on the engagement of the springpres-sed ball elements 18a incontacting the bushing shoulder or edge 20, but such supporting functionis borne by the tight compression-producing forces which the descendingpost developsr'for application to the ball ele-,

ments 18 and the walls of the bore 14. The retainer isthus caused totravel in about one to'two ratiofwith" 'the post *as the latter moveseither downwardly or up; Wardly on its working strokes, so that thespring-pressed' ball elements 182: donot again, support the retaineruntil "Q'Inthe form of the invention illustrated'in Fig.3; the

' same features of control and operation a re' esse'ntiallyr present,but in this form the ball elements shown tat- 18b, 'areflforced inwardlyandradially of the reta ne 16 by V the action'of' the resilient; ring'or-band 2}; In this constructio'n, the retainer i-ssupported -firornthe lower end of the post 1 5 when the latter occupies itselevated-position 1 through engagement with am -annular recess or'groove a 23 formed-.inand extending around the lower part of the V ipost;- The openings 17b of the-"retainer '16 in this latter V form ofmy'i'nventio n are oppositely formedor disposed V; 'with respect to theopenings 7170 so th atrtherelativelyr enlarged regions of the openings17b'are disposed toward f the outside of'th'e retainer rather-3'thantheinner side; 7

thereof, V V motion-disclosed in Fig. 3, when the post In th condescends'on its working stroke; the ballelernents 7 181) "are,

displaced outwardljfifthus releasing-the jassiociated re,

tain'er from itsassociation of suspendedsupport from f the lower end-ofthe post; However; at this-time the descending post engages 7 ballelements 18 disposed ime'ngag'ed elements 18 tinder compression-{andcausing regulated'descent of the-retainriatla 'l'qwerirate of travel'thanthe descending; post, as; previously-explained. when, [i the postreturns to -its elevated position after completing,

its gcycle of -moveinent, the ball elements isb arel'again i seated inthe'reces's or girooveg23to;supporttheretainer, 'or sleeve} f i I Thesemember's-rarev slidably' mounted in the openings ment with the postgroove 24 and its shoulder 25 by the spring ring 22, the latter beingseated in'notches formed in the outer ends of the latch members. It willbe evident that with the use of this construction, when the postdescends on its working stroke, the engagement of the conical wallsurfaces of the groove 24 with the inner ends of the latch members 26,results in outward radial movement of the latch members against theresistance of the spring ring 22. The sleeve is thus released forcontrolled downward movement with the post as the post engages the ballelements 18 to impart compressive loading thereto.

Through the use of the means described, or the equivalent thereof, thevertically movable'ball-bearing-carrying retainer or sleeve members ofantifriction die set guide assemblies are positively supported orretained against movement in a predetermined positional relation to theassociated movable and stationary members of the guide assembly.Further, the construction of the positioning means of the presentinvention is such that the retainersupporting function thereof isreleased or removed automatically with the descent of the moving memberof the assembly on its working stroke, so that the retainer member willbe caused positively to move linearly with the associated movable memberat a controlled relative rate of travel throughout the full workingstroke of said movable member. When the latter returns to its normal orstarting position the retainer member returns with it andoccupies apredetermined positional relationship therewith. At this time the ballelements of the retainer member are relieved of the compressive forcesresulting from their simultaneous contact with contiguous surfaces ofthe movable and stationary guide members of the assembly. The telescopicrelation between the guide members during a working stroke and theinterposition of the retainer member with its ball ele ments, enablesthe retainer member to be movably positioned in its established relationwith said guide members. The retainer, it will be observed, moves inunison with an associated post when the bearing elements are unloaded,but when said elements are loaded or pressure confined between the postand bushing, the postcarried retainer holding means arereleased to admitof independent relative movement of the retainer with respect to thepost, or other movable member normally carrying the same.

Various other modifications maybe made within the scope of the followingclaims, including the employment of posts of square or polygonalcross-sectional formation and roller bearing elements rather than ballbearing elements. Also, dual walls of sheet metal may be used in theformation of the retainers rather than the solid wall types shown.

I claim:

1. Guide mechanism for the die sets of presses, comprising: a stationarymember; a movable member disposed in coaxial order with the stationarymember and movable longitudinally into and out of interfittingrelationship therewith; a retaining sleeve occupying an annular spaceformed between said memberswhen the latter are disposed in interfittingorder; ball elements rotatably movable in socket-forming openingsprovided therefor in the wall of said sleeve and having antifrictionguiding engagement with the adjacent wall surfaces of said membersdefining said space, said elements when in simultaneous contact withsaid member surfaces being placed under compression loading whereby tocause said sleeve to travel linearly concomitantly with and at acontrolled rate relative to that of the associated movable guide member;and means for positively supporting said sleeve in a fixed predeterminedpositional order with respect to said movable and stationary guidemembers when the movable member assumes a position removing the samefrom compressive engagement with the ball elements.

pliances of the type embodying interfitting stationary and movable guidemembers. there being a floating ballbearing retaining sleeve movablyinterposed between said members, the bearings of said sleeve receivingcompressive loading through opposing simultaneous contact with saidmembers during working mov'ement thereof; and retractable latch meansfor supporting the sleeve of said appliance in a definite positionalorder in relation .to said members when support normally afforded saidsleeve through compressive loading of said bearings is removed as aresult of change in relative positions of said members. 3. Alignmentmaintaining antifriction guide means for die sets, comprising:relatively movable axially arranged socket and post members; a sleeveformed for movable interposition between said socket and post memberswhen the latter are disposed in interfitting order; ball bearingsrotatably positioned in spaced seat-forming openings provided thereforin the cylindrical wall of said sleeve, said bearings being of uniformdiameter and arranged in said sleeve openings to project equidistantlybeyond the inner and outer wall surfaces of the sleeve for simultaneouscompressive contact with adjacent wall surfaces of said socket and postmembers during interfitting longitudinal movement of one of saidlast-named members with respect to the other, whereby to producemovement of the sleeve in a linear direction concomitantly with relativemovement between said members; and means operative when said membersattain relative positions in which the bearings of said sleeve arerelieved of sustaining compressive forces produced by simultaneouscontact of said bearings with said members to effect the support of saidsleeve in a definite operational position relative to said members.

4. Alignment maintaining antifriction guide means for die sets,comprising: relatively stationary and movable axially arranged socketand post members; a sleeve positioned for longitudinal movement betweenthe post and sleeve members, said sleeve being formed with spacedopenings for the rotatable reception of ball elements,

a the latter being of such diameter as to engage simultane- 5. ,Die setaligning and guiding means as defined in claim 4, and wherein saidlatching means are disposed I radially of the guide means and havereleasable engagement with the movable guide member when the latter isadvanced on an operating stroke.

6. Die set aligning and guiding means as defined in claim 4, and whereinsaid latching means comprises at least one of said ball elementspositioned in the opening provided therefor in said sleeve for radialmovement; and resilient means positively displacing the latching ballelement radially to maintain the same in a position in which itprotrudes yieldably on one side of the sleeve to a greater extent thanthe remaining ball elements, said protruding ball element havingreleasable sleeve-supporting contact with one of said guide members whenthe latter occupy relative positions in which said ball elements arerelieved of compressive loading.

7. Die set aligning and guiding means as defined in and by claim 4, andwherein said latching means includes in said sleeve an enlarged seatingopening for the reception of at least one of said ball elements, saidseating 7 "7 sleeve t i gre erextent t an rem ining. ball ele 'when thepost and; socket members occupying'relqtiye positions in whicht s aidsleeve-c arried ball elements. erre-v relieved of cornressive loading;and resilient means 'co '7 operative Wlih; theprbtruding ball elementtomaintain the; same,;intheabsence of preponderant opposing forces in;itsposition'of'rnaximum protrusion inwhich said element engages one of saidmembersin retractable sleeves n'pportingIelation, i i

' 8-. The/combination with;antifrietion die set guiding and'ali gn ingmeans, said means being o'f the type; em

bodyin'g ,zi;. bnshingmember carried by one of the plates of a diesetand having a bore arranged to receive axially a post member earriedbyanotl le die set plate, said membersibeingjrelatively movable to cause the post member.

to m oyeintoi and out of the-bore of said bushing member there being afloating sleeve arranged for relatiye move-. ment longitudinallyandaxially. of and between said member, the cylindrical wall of said sleevebeing formed with se ating iogening s for the receptionhof a' pluralitying movements of saidmembersb No references cited.

